Notes from 'CCNA Voice 640-461 Official Certification Guide - 2nd edition by Jeremy Cioara and Michael Valentine
Table of Contents
Trad Voice vs Unified Voice
Analog
- Loopstart - offhook connects tip to ring, and 48V DC flows to CO through phone. signals COs that can receive incoming call or place outgoing call
- glare can happen when inbound and outbound calls happen at same time
- Groundstart - ground both wires temporarily, CO sends dial tone on the line. signals CO that outbound call is about to happen.
Supervisory signaling - on hook, off hook, ringing
information signaling - dial tone, busy, ringback, ...
address signaling - dtmf, pulse
Digital
TDM
T1 from is 193 bits
CAS (Channel associated signaling - steal bits from voice bw)
T1s use 8th bit on every 5th sample in each DS0
CCS (Common channel signaling - dedicated signaling channel)
24th slot is used on T1s
17th slot used on E1s
e164
Max of 15 digits in length
country code, national dest code, subscriber number
NANP breaks down to
- country code
- area code
- CO/Exchange code
- station code
VoIP
Benefits
- reduced cost of communicating
- reduced cost of cabling
- seamless voice networks
- take phone with you
- IP softphones
- unified email voicemail fax
- increased productivity - multi device ring
- feature rich comm
- open compatible standards
Voice packet conversion
avg human ear hears frequencies form 20-20,000 Hz
human speech uses freqs from 200-9000 Hz
telephone channels typically transmit freqs from 300-3400
Nyquist recreating 300-4000Hz - sample at 2x the highest frequency
8000 samples per seconds x 8 bits each 64kbs
alaw and ulaw are exact opposites 0s and 1s
MOS 1-5 'nowadays, a chicken leg is a rare dish'
Codec bw MOS typical
G711 64kbps 4.1
ILBC 15.2kbps 4.1
G729 8kbps 3.92
G726 32kbps 3.85
G729a 9kbps 3.7
G728 16kbps 3.61
G729a - sacrifices audio qual to achive more proc efficient coding
G729b - supports VAD
MOS can be bad...
DSPs
calc - http://www.cisco.com/web/applicat/dsprecal/index.html
PVDM2-8 - .5 DSP chip
PVDM2-16 - 1 DSP chip
PVDM2-32 - 2 DSP chips
PVDM2-48 - 3 DSP chips
PVDM2-64 - 4 DSP chips
DSP resources can handle double # of med-complex calls per dsp as high
Med Complex - G711 G726 G729a, G729ab
Hi Complex - G728 G723 G729 G729b iLBC
RTP/RTCP
RTP even # UDP port
header - payload type, seq number, time stamp
UDP port 16384-32767 by default
1 way (need 2 for conversation)
RTCP reports stats odd number port above RTP
- packet count, delay, loss, and jitter
- gets sent at least 1x per every 5 seconeds
- CME can log and report info
Cisco UC
CME
- Max phones in 3945E ISR G2 - 450
- CLI or Cisco Config Professional (CCP) GUI
- SCCP or SIP to phones
CUE
- 2 form factors
- Internal Services Modele (ISM) - Installs internal to CME rtr and uses solely flash for storage
- Service Module (SM) - installs externally and uses hard drive ofr storage. Can handle 10x as much as ISM?
- upgrade from AIM and NM modules which where used in 1st gen ISR (1800, 2800, 3800)
- Linux based OS
- access and manage from IOS of CME rtr or through GUI
- up to 32 max ports, 300 mailboxes, 600 storage hours
- Voicemail, auto-attendant, IVR, T.37 faxing (TIFF), SRSV (Surviavable Remote Site Voicemail for primary voicemail, standards based (SIP)
CUCM
- Audio / Video Telphony support
- Appliance bases operation
- Redundant server cluster
- 30000 unsecure sccp/sip phones, 27000 secure sccp/sip phones
- Intercluster and gw control and communication
- Disaster Recover System (DRS)
- VMWare Virtualization Support
- Dir svc support or integration
CUCM cluster communication
- 1 pub, up to 8 subs, TFTP svrs, media svrs
- up to 3 CMs in CM group
- smaller environtments 500- - pub can be use dfor call proc and db mgmt, exceed 1250, create dedicated TFTP
- DB - master writable db on publisher
- during pub failure, user-facing features will still work (DND, MWI, CFA) and replicate to other subs (CUCM5+)
- Runtime data - e.g. device registers - ICCS Comm - TCP ports 8002 - 8004
- device registers
- call initiation
- call disconnect
- etc.
- Primary svr is call processing svr, not pub
CUCM Business Edition
Up to 500 IP phones no server redundancy (clustering)
Unity Connection
- CUE - 300 max mailboxes
- CUCM Business Edition - 500 max mailboxes
- Unity - 15000 max mailboxes (win svr) - active/passive
- Unity - 20000 max mailboxes (appliance) - active/active - supports personal call xfer and speech recognition
- Appliance based platform
- up to 20000 mailboxes per svr (pair)
- up to 250 voicemail ports per server
- access voicemail from anywhere
- LDAP integration
- Exchange support
- VPIM support
- Active/Active HA
- Can support CME deployments (w/ central Unity Conn VM)
CUP
Unified Presence
- Enterprise IM - Jabber Extensible Communication Platform (XCP)
- Message compliance (logging all communication
- Interdomain federation (e.g. w/ Google Talk or WebEx Connect
- Jabber SCP extensibiilty = p2p file sharing, app sharing, vid-conf, etc. Integrates with Dir Svcs, DBs, web portals.
- Secure messaging
CUPC
Cisco Unified Personal Communicator - IM client with soft phone, presence, IM, visual voicemail, employee directory, comm history, video, web conferencing. LDAP auth, change, multiuser chat, peristent chat (in 'rooms'). Can see on/off hock on phones.
Phone concepts
Plugs in back
- RS232 to connect to expansion module (7914, 5, or 6)
- 10/100 SW
- 10/100 PC
- handset
- headset
POE
- Switch POE (prestandard or 802.3af)
- Power Patch Panel PoE (prestandard or 802.3af
- power patch panel or inline power injector/coupler
- Cisco IP Phone Power Brick (wall power)
- 802.3af PoE standard, or Cisco proprietary
VLANs
Broadcast domain, IP Subnet
- Increased performance
- Improved manageability
- Phys topology independence
- Increased security
- VLAN tags get stripped before they hit PC
- Phone has mini switch that can tag data vlan packets and voice vlan packets separately
- Config the IP phone port as access (untagged) supporting tagged traffic from IP phone
config term
vlan 10
name VOICE
vlan 50
name DATA
int range fa0/2 - 24
switchport mode access
spanning-tree portfast
switchport access vlan 50
switchport voice vlan 10
With this config, only an attached Cisco IP Phone will be able to access the voice VLAN. Learns from it via CDP. non-Cisco IP phones have to be manually configured with voice VLAN number
Cisco IP phone boot proc
- PoE (Cisco proprietary or 802.3af
- switch delivers voice vlan info via CDP
- DHCP req asking for IP address on voice vlan
- DHCP response including addr, domain, gw, option 150 tftp svr
- contacts TFTP server and downloads cfg file, including list of valid call processing agents
- CML config file have filename in format SEP<IPPhoneMACAddr>. SEP stands for Selsius Ethernet Phone (company Cisco acquired when first began mfging VoIP tech
- If no phone config file exists, phone will request XMLDefault.cnf.xml for auto-registration
- phone attempts to contact processing svr (primary svr) listed in its cfg file. If 1st fails, go to 2nd, than 3rd.
- IP phone ids itself by its mac addr. Call proc svr matches in db, and sends operating cfg to phone (dir/line number, ring tone, softkey layout, etc). Sent using SIP or SCCP?
Configuring Rtr based DHCP svc
config term
ip dhcp excluded-address 10.1.1.1 10.1.1.9
ip dhcp excluded-address 10.1.2.1 10.1.2.9
ip dhcp pool DATASCOPE
network 10.1.2.0 255.255.255.0
default-router 10.1.2.1
dns-server 10.1.3.10
ip dhcp pool VOICESCOPE
network 10.1.1.0 255.255.255.0
default-router 10.1.1.1
option 150 ip 10.1.3.20 (if using CME, make this
same as default-router?)
dns-server 10.1.3.10
'if you have a central dhcp svr use
ip helper-address <DHCP server IP address>
Configuring Rtr to receive time via NTP
config term
ntp server 10.1.3.30
clock timezone NYC -5 (assuming source is UTC)
ntp master 4 (deliver data/time info to requesting clients
marking it with stratum
number 4)
clients could be phones or CME
exit
show ntp associations
CME
CCP, CME GUI, and CLI overview
- CCP (GUI) - Cisco Configuration Professional - simple config and troubleshooting for vast majority of CME features
- CME GUI (integrated) - HTML and JAR files, usually pre-installed, but can be loaded via downloadable TAR package
- MACs, dial-plan, hunt groups, etc...
- runs from Flash
- focused on telephony aspects
- CLI - more complete, less efficient, do all troubleshooting here, show or debug commands
- accessible via console port, telnet, ssh
- majority accessible via telephony-service config mode
conf t
telephony-service
?
exit
exit
show ephone registered
ephone-1[ 0] Mac: 0ABC.0123.4567 TCP socket:[ 1] activeLine: 0 REGISTERED in SCCP ver 17/ 9
mediaActive: 0 offhook: 0 ringing: 0 reset: 0 reset_sent: 0 paging 0 debug: 0 caps:
8 IP: 10.1.1.40 32454 5432 keepalive 16651 max_line 8
button 1: dn 1 number 2225 CH1 IDLE CH2 IDLE
Preferred Codec: g711ulaw
Endpoints and End users - CME
tftp svr cfg
Point CME TO Ext TFTP Svr
cnf-file location tftp:// < ip address of TFTP server >
(from telephony service configuration mode.
User CME as TFTP
dir flash:/phone/7941
tftp-server flash:/phone/7941/<loadname>.loads alias <loadname>.loads (redirects load tftp reqs to path
make sure all files available via 'alias' command
- Files downloadable from Cisco website in TAR archive
Base CME Cfg
telephony-service
ip source-addr <ipaddr>
max-ephones 15
max-dn 30
ephone-dn 1 (from 1-150, but lower than max-dn)
number 1200
ephone-dn 2 dual-line
number 1201
ephone-dn 3 dual-line
number 1202 secondary 6175551202
ephone 1
mac-addr 0123.4567.8901
button 1:2 (button 1 uses ephone-dn 2)
(: indicates normal ring)
button 2:3 3:1
restart (restart phone (reboot) and download cfg from tftp)
show ephone
<...list of ephone params...>
- If phone status DECEASED - CME rtr has lost connectivity to phone via TCP keepalive
- if phone status UNREGISTERED - CMR rtr closed connection to phone normally
- single-line ephone-dn - only one line, 2nd call gets busy
- dual-line ephone-dn - line can take 2 simultaneous calls - useful for call waiting,conf call, consultative transfers, etc.
- octo-line - in newer IOS versions - 8 calls per line (e.g. recpetionist, shared lines, conf resource, ...)
- Can use Cisco Configuration Professional (Web interface) instead
User Cfgs in CME
ephone 1
username Joe password Dapassword
pin 555121
button 1:1
restart
exit
ephone-dn 1
name Sarah Smith
exit
CME CCP Config (GUI)
Cisco Config Professional
Go to Configure > Unified Communications > Telephony Settings to configure max-ephones, max-dn, ip source addr, etc.
Click 'Refresh' button to force sync of config on box.
CCP will show command line config to match up with your config
Bulk import wizard to the right (allows import of CSV files)
Config Extensions
Configure > Unified Communications > Users, Phones and Extensions > Phones
User Settings/Names
Creates user db which can be searched on phone as local directory
Configure > Unified Communications > Users, Phones and Extensions > User Settings
Click Phones/Extensions tab at top of the Create User window to associate phone, extensions and user account.
Type free form IOS commands
Configure > View > IOS Show Commands
CME Dialplan
show voice port summary (ephone-dns show up as EXFS ports)
3 common areas of config
- Signaling
- Call Progress tones
- Caller ID information
FXS
voice-port 0/0/0
signal loopStart (or groundStart) - SIGNALING
cptone US (or some other 2 letter country code) - CALL PROGRESS TONES
station-id name Joe Smith - CALLER ID INFO
station-id number 8005551234 - CALLER ID INFO
FXO
voice-port 0/1/0
signal loopStart (or groundStart) - SIGNALING
station-id name Joe Smith - CALLER ID INFO
station-id number 8005551234 - CALLER ID INFO
dial-type dtmf (or pulse)
ring number (number of rings before pick up)
Digital circuits
show controllers t1
controller t1 1/0
framing esf (or sf)
linecode b8zs (or ami)
clock source line (or free-running or internal (provide clocking))
ds0-group 1 timeslots 1-12 type e&m-wink-start
ds0-group 2 timeslots 13-24 type fxo-loop-start
ds0-group commands automatically creates voice ports PSTN carrier typically uses FXO loop start signaling
PBXes often support one of the E&M signaling types
show voice port summary will show port:ds0group (e.g. 1/0:2 for channels 13-24 as fxo-loop-start
isdn switch-type primary-dms100 (or primary-5ess or ...)
controller t1 1/1
pri-group timeslots 1-24
pri-group commands automatically creates voice ports
show voice port summary will list channels 01-23 associated with port 1/0:23
These commands will not show up in 'show ip interface brief'
channel 23 (time slot 24) is signaling on T1 ISDN
channel 16 (time slot 16) is signaling on E1 ISDN
make sure you have enough DSPs to support
Dial Plan
POTS Dial peers
dial-peer voice 1101 pots
destination-pattern 1101
port 0/0/0 (probably a FXS)
dial-peer voice 2000 pots
destination-pattern 2...
no digit-strip (do not strip any (POTS) explicitly defined digits (e.g. the 2 above)
port 1/0:23 (pri)
dial-peer voice 10 pots
destination-pattern [2-9]..[2-9]......
prefix 1 (prefix 1 before outgoing dest pattern)
port 1/0:1
dial-peer voice 9011 pots
destination-pattern 91[2-9]..[2-9]......
forward-digits 11 (right justified will forward from 1 onwards)
port 1/0:1
num-exp 4... 5... (replace all 4 digit numbers starting with 4 to
4 digit numbers starting wiht 5
to change type of dial peer (e.g. to voip) 'no dial-peer voice 1101' or whatever tag...
show dial-peer voice (for details on each dial-peer)
show dial-peer voice summary
AD PRE PASS OUT
TAG TYPE MIN OPER PREFIX DEST-PATTERN FER THRU SESS-TARGET STAT PORT
1101 pots up up 1101 0 up 0/0/0
debug voip dialpeer (to analyze digit processing)
show dialplan number <number>
(shows all matching dial peers in order in which router will use them...
more specific matches are 1st)
VoIP Dial peers
dial-peer voice 2001 voip
destination pattern 3...
session target ipv4:<ipaddr> (or dns:<name>)
codec g711ulaw (or g711alaw, g729r8, etc - if codec doesn't match - reorder)
dial peer wildcards
. | matches any dial digits 0-9 or * |
+ | matches one or more instances of preceding digit |
[] | matches range of digits. ^in here designates 'do not match' |
T | matches any number of dialed digits from 0-32 digits |
, | inserts a 1-second pause between dialed digits |
# is not a wild card but forces immediate processing of dialed number
if you use T, recommended to use .T. which requies user to dial at least one digit. Otherwise no digits dial could match on T302 interdigit timeout
NA sample PSTN dest patterns
[2-9]..[2-9]...... | 10 digit dialing |
1[2-9]..[2-9]...... | 1+10 digit dialing areas |
[469]11 | service number 411, 611, 911 |
011T | international dialing |
PLARs
voice-port 0/0/0
connection plar 1102 (when someone picks up phone - dial 1102)
inbound dial peers
match inbound dial peers through following 5 methods
- incoming called-number - DNIS
- answer-address - ANI
- destination-pattern - ANI
- port dial-peer - incoming POTS dial peer
- use dial peer 0